Known latch assemblies for the opening/closing and locking of closures of the type in which at least one bolt is manoeuvred using a handle are shown in, for example, U.S. Pat. No. 4,548,432 (Bengtsson), hereby incorporated by reference. The assembly comprises a lock casing attached to an espagnolette edge bar. The lock casing contains a locking and manoeuvring mechanism. The bar and the lock casing are mounted in a recess in, for example, a door. An espagnolette rod is displaceable along the door edge and is arranged as a latching rod for manoeuvring at least one espagnolette bolt. A handle in the locking and manoeuvring mechanism acts on a bevelled bolt and the espagnolette rod. When the handle is in a rest position, the espagnolette bolt is retracted into an espagnolette edge bar recess while the bevelled bolt is extended. In a locking position, the espagnolette bolt is extended out from the espagnolette edge bar recess to cooperate with a locking element affixed to, for example, a door frame surrounding the door.
Although the above-described latch assembly has been shown to operate satisfactorily, at least two apparent drawbacks are associated with the assembly.
Firstly, when the assembly is in the locking position, any force exerted on the espagnolette bolt or the espagnolette rod, for example by an intruder trying to break open the closure, is transmitted to the locking and manoeuvring mechanism via the espagnolette rod. The locking and manoeuvring mechanism thus has to be made sufficiently robust to withstand this force in order for the locking function to be maintained. This results in a heavy and expensive construction of the locking and manoeuvring mechanism.
Secondly, should the espagnolette rod be cut through from outside the door, for example by an intruder, and the thus severed espagnolette rod parts are pushed apart from each other, the at least one espagnolette bolt may fall under the effect of gravity from its locked position to an opened position in which it is drawn into the espagnolette edge bar recess, thus facilitating unauthorized opening of the door.